Improvement in hoisting-machsnes



ot this specification.

l v worm-wheel, racks B B'.

ATNT NEIGE.

WILLI-AM MILLER', or oINcINNAZrI, oHIo.

'iwipsevnwien'r an meterme-MACHINES.

Specification forming part ot Letters Patent No. QSJIQ, dated July 4, 1865.

i To all whom it may concern.-

Beit known that I, WILLIAM MILLER, of Cincinnati,Hamiltoncounty, Ohio, have iuven ted a new andus'eful Improvement in Hoisting-Machiues or Elevators; and l do hereby declarcthe following to be a full, clear, and exact description thereof, 'reference being had to the accompanying drawings, making apart The present 'nvention relates to an improvement on the device patented to me on the 12th day of May,

and eliicient adaptation of the worm principle to an elevator or hoisting-platform. v

Figure lis a perspective view of a. portion of a. hoisting-machine included between two` consecutive loors. Fig. 2 is atransverse section below the platform, and looking upward.

A and A represent customary. hatchways, anked by worm-racks or segmental screwsB B', which-extend `vertically from the lowest to the highest floor, and which ure irrnly secured 'to and supported by suitable stanchions, G C'.

1 is a platform, to which is attached a suitable frame or housing, E, containing a large F, which meshes equally in both 'The weight of the platform is received directly by the worin-wheel, near the margin of the latter, through the medium of rollers G, whose hearings depend' either from the platform orfronrthe upper part ot' the housing E. The worm-wheel Elias ahah, I, which is connected to the outer ring or margin of the wheel by alight plate, J, or by spokes. The hub I is secured to a shaft or axis, H, journaled vertically :in the frame E. The duty of the shaft H is merely to hold the worm to its proper central position betweenv the racks, the

1863; and it consists in a more simple, secure,

Worm itself being supportedwholly by the racks. The worm F has on its under iside a bevel-wheel, K, which receives a vdriving-pinion, L, journaled horizontally in the frame E, and having a pulley, M, around which and Aand another pulley, N, the endlessilriving-belt 0 is wrapped.

`A great' practical advantage incident to the t luse of the single worm-wheel meshing equally 'in both racks consists in the perfect equality I of strain and bearing, and in the directtransmission of pressure from the platform through the rollers and worm to the racks, and also in the freedom from strain and .displacement to which the journals of small and separate wormwheels areV liable. tage is that each revolution ot' the' worm may be made to produce a more rapid -ascent or descent ot the platform with a. less abrupt pitch or declivity ofthe thread, v

'An inferior modification ot' my device may have the platform D supported upon the worm F through the medium of e rim or circular flange, in place of' the rollers G.

I claim herein as new and ot' my invention- 1. An elevator platform having a single worm-wheel, F, which meshes within two or more opposite worm-racks, B B', substantially as set forth. 4 V

2. Au elevator-platform supported by rollers Gr, or their equivalents, on a single worm'- wheel, F, restingin worm-racks B B', substantially as set forth. V

In testimony of which invention I hereunto set my hand.-

Witnesses:

Gno. H. KNIGHT, JAMES H. LAYMAN.

Another obvious .advan WILLIAIII MILLER. 

